Well the blank parts of a page thing could have been the bug when the plugin was called in the loop. That should be fixed now.
It sounds like your hosting company doesn't like to do software updates after installing the OS off of a disk. CentOS has a wiki page for updating PHP to 5.2.x and it is quite simple:
# rpm -qa |grep php
# yum update
# service httpd restart
The first checks for installed php components, the second does the install, the third restarts apache.
I noticed one thing with the checking code, I look at the superglobal
PHP_VERSION for the check, but report using
phpversion(). If after updating you get where it says a version over 5.2 in the message (e.g. the warning becomes non logical), then it may be something with the global.
The message should have contained two version numbers in it, like the example JLeuze posted:
Your PHP version is too old, please upgrade to a newer version. Your version is 5.1.6, this plugin requires 5.2.0
Where "5.1.6" would be what ever version of PHP your site is running. If that is blank, then your host is trying to hide their PHP version. If that version is still 5.1.x or 5.0.x (where x is a number), then your host lied to you about upgrading the PHP version. If that version number is 5.2.x (where x is a number), then as explained above,
phpversion() are for some reason two different versions (and something I need to look into).